package com.bootdo.contract.utils;

public class Map {
    private static double EARTH_RADIUS = 6378138.0;

    private static double rad(double d)
    {
        return d * Math.PI / 180.0;
    }

    /**
     * 计算是否在圆上（单位/千米）
     *
     * @Title: GetDistance
     * @Description: TODO()
     * @param radius 半径
     * @param lat1  纬度
     * @param lng1  经度
     * @return
     * @return double
     * @throws
     */
    public static boolean isInCircle(double radius,double lat1, double lng1, double lat2, double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) +
                Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000) / 10000;
        if (s > radius) {//不在圆上
            return false;
        } else {
            return true;
        }
    }
}
